Key findings of the IPCC WG I Fifth Assessment Report

Transcription

1 Key findings of the IPCC WG I Fifth Assessment Report R. Kolli, WMO Based on IPCC and WCRP Resources Yann Arthus-Bertrand / Altitude

2 What is happening in the climate system? What are the risks? What can be done? Courtesy: Jean-Pascal van Ypersele, IPCC Vice-Chair

3 Headlines of the IPCC WGI 5 th Assessment Report Warming is unequivocal. Many observed changes are unprecedented on timescales of decades or millennia Human influence on climate is clear Climate will continue to change in future Limiting future climate change will require substantial and sustained reductions in emissions

4 New findings since the Fourth Assessment Report Increased certainty of a human influence on climate Improved observations & models and increased understanding of many components of the climate system New emission scenarios and projections of climate change beyond 2100 to 2300 Sea level rise projections include ice-sheet dynamical changes Estimates of the total allowable global emissions in order to limit temperature rise to e.g. 2 C above pre-industrial

5 Global mean surface temperatures increased by 0.89ºC between 1901 and 2012 Globally averaged surface temperatures IPCC (2013) Figure SPM.1

6 Almost the entire globe warmed between 1901 and 2012 C over period IPCC (2013) Figure SPM.1

7 Arctic summer sea ice extent has decreased IPCC (2013) Figure SPM.3

8 Global mean sea level increased by 0.19 m between 1901 and : 1.7 mm/yr : 3.2 mm/yr IPCC (2013) Figure SPM.3

9 Multiple lines of robust and compelling evidence support the conclusion that many aspects of the climate system have changed

10 Regional Observed Changes in Climate Indices

11 How large is the projected change in surface temperature compared with internal variability? IPCC (2013) Figure SPM.8 Box 12.1: Methods to Quantify Model Agreement in Maps Stippling indicates regions with large changes and high model agreement Hatching indicates regions with small changes or low model agreement

12 Climate extremes: more hot and fewer cold extremes IPCC (2013) Table SPM.1

13 More hot and fewer cold days and nights as global temperatures increase IPCC (2013) Figure 12.13

14 The contrast between wet and dry regions and wet and dry seasons will increase* *with some regional exceptions RCP2.6 RCP8.5 Stippling: changes are large compared with internal variability (greater than two standard deviations of internal variability), and at least 90% of models agree on sign of change IPCC (2013) Figure SPM.8

15 The rate of sea level rise is very likely to increase IPCC (2013) Figure SPM.9

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21 Examples of reworking the atlas using data provided

22 CORDEX initiative Coordinated Regional Downscaling Experiment Sponsored by the World Climate Research Programme cordex.ipsl.jussieu.fr/ Coordinate high-resolution regional climate modeling unified protocols, experiments, format, variables, etc. Provide a set of high-resolution Regional Climate Scenarios for the majority of land-regions of the globe Make these data sets available and useable to the impact and adaptation communities 14 CORDEX Domains defined (South-East Asia is latest)

23 Establishment of IPOC at SMHI, Sweden

24 CORDEX Phase I experiment design Model Evaluation Framework Climate Projection Framework AMIP like Multiple regions (Initial focus on Africa) 50 km grid spacing CMIP like ERA-Interim LBC Regional Analysis Regional Databanks RCP4.5, RCP or Decadal predictions , , Multiple AOGCMs

25 CORDEX Phase II Added-value of downscaling compared to global models: target higher resolution (25km or finer), systematic comparisons Flagship Pilot Studies (FPS), high resolution (few km) regional climate simulations in selected regions with good observational records Room for innovative science: multiple (possibly 2-way) coupled nests Earth-System downscaling approach (coupling with ocean, land, cryosphere, etc) Promote systematic use of ESGF within CORDEX (see CORDEX 2013 conf final report for further details)

26 Further Information Yann Arthus-Bertrand / Altitude